The present invention is directed to an envelope opener. In particular, the invention is directed to an envelope opener in which three edges of an envelope are sheared one edge at a time under control of a microcomputer. The invention is further directed to an envelope opener in which an envelope is aligned for shearing by contacting the edge to be sheared rather than adjacent edges of the envelope. It is not required that any of the envelope edges by pre-weakened.
Automatic envelope openers are known in the art. For example, see U.S. Pat. Nos. 3,590,548, 3,764,049, 3,875,722 and 3,822,523. Heretofore, high speed automatic envelope openers operated at fixed rates under control of relatively primitive electro-mechanical components. In certain envelope opening machines, three edges of the envelope had to be pre-weakened before the envelope could be opened and its contents exposed. In other machines, the edge of the envelope to be sheared was aligned for shearing by contacting one or more of the remaining envelope edges. This frequently resulted in misalignment of the envelope and, accordingly, incomplete severing of the an envelope edge. In addition, such machines required cumbersome mechanical structure for guiding and aligning the envelope immediately prior to shearing.
To date, no design has been proposed for an envelope opening machine which can monitor the advance of an envelope through the machine. There has been no design proposed for such an envelope opening machine which is fully automated and continuously operated under the control of a microcomputer. There has, in particular, been no design proposed for a microcomputer controlled envelope opening machine which is capable of automatically indicated a jam condition and automatically shutting down under such condition.